Breakthrough development of terahertz quantum cascade lasers

With the development of groundbreaking components for terahertz quantum cascade lasers, a huge leap has been made in the field of laser technology. A group of researchers have successfully designed a broadband single-chip external coupler with the potential to redefine the functionality of terahertz QCL.

The new external coupler is fundamentally based on planar bimetallic waveguides. Its design is specifically aimed at addressing the long-term challenges of reflectivity design and broadband narrow beam transmission in terahertz QCL. The outstanding feature of this external coupler is its ability to fine tune the mirror reflectivity of the waveguide. This is achieved by using efficient reverse design algorithms to shape the end face.

The terahertz laser radiation generated by the system is combined with broadband patch array antennas. The combination of these components leads to the convenience of surface emission. The entire system, including all its components, has been optimized to support octave frequency crossing in the range of 2-4 THz.

These advances have been put into practice through demonstrations of broadband surface emitting terahertz quantum cascade laser frequency combs. This special laser frequency comb has already demonstrated impressive performance indicators. It can output a power of 13 milliwatts and has an optical bandwidth of over 800 gigahertz and a single lobe far-field mode. It still maintains a beam divergence of less than 20 degrees in both horizontal and vertical dimensions.

In addition, this work plays a crucial role in the empirical observation of terahertz waves generated in a cascaded manner under non collinear phase matching conditions in terahertz parameter generators. Researchers effectively induce cascades using high-power seed beams to detect new high-order terahertz waves near the end face.

This development is a major step forward in the fields of terahertz wave sources, parameter detection, and amplification. It not only enhances the output power of terahertz sources, but also provides a way for theoretical exploration of parameterized TH wave generation.

This breakthrough represents significant progress in the field of laser technology and may pave the way for new possibilities for terahertz applications. It reflects the intricate interaction between technology and humanity, further blurring boundaries and expanding our understanding of possibilities.

Source: Laser Net